• Title/Summary/Keyword: DTI

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The Emerging Role of Fast MR Techniques in Traumatic Brain Injury

  • Yoo, Roh-Eul;Choi, Seung Hong
    • Investigative Magnetic Resonance Imaging
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    • v.25 no.2
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    • pp.76-80
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    • 2021
  • Post-concussion syndrome (PCS) following mild traumatic brain injury (mTBI) is a major factor that contributes to the increased socioeconomic burden caused by TBI. Myelin loss has been implicated in the development of PCS following mTBI. Diffusion tensor imaging (DTI), a traditional imaging modality for the evaluation of axonal and myelin integrity in mTBI, has intrinsic limitations, including its lack of specificity and its time-consuming and labor-intensive post-processing analysis. More recently, various fast MR techniques based on multicomponent relaxometry (MCR), including QRAPMASTER, mcDESPOT, and MDME sequences, have been developed. These MCR-based sequences can provide myelin water fraction/myelin volume fraction, a quantitative parameter more specific to myelin, which might serve as a surrogate marker of myelin volume, in a clinically feasible time. In this review, we summarize the clinical application of the MCR-based fast MR techniques in mTBI patients.

Construction of the Fiber Pathways from Diffusion Tensor Imaging and Comparative Analysis of the Fiber Pathways of Alzheimer patient and Normal People (확산 텐서 영상으로부터 신경섬유 경로의 생성과 알츠하이머 환자와 정상인의 비교 분석)

  • Lee, Wook;Park, Byung-Kyu;Han, Kyung-Sook
    • Proceedings of the Korea Information Processing Society Conference
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    • 2013.05a
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    • pp.747-750
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    • 2013
  • 알츠하이머병은 치매의 주요 원인 중 하나로 기억, 판단, 언어 등의 지적 기능의 감퇴뿐만 아니라 인격, 행동양상 장애 등을 동반하며 결국은 환자를 죽음에 이르게 하는 위험한 병이다. 본 연구는 뇌 백질의 비등방성을 잘 보여줄 수 있는 확산 텐서 영상 (diffusion tensor imaging; DTI) 데이터로 부터 신경섬유 경로를 생성하고, 알츠하이머병 환자와 정상인의 신경섬유 경로의 특징을 비교 분석 하였다. FSL 프로그램을 사용하여 생성한 신경섬유 경로에서 알츠하이머 환자와 정상인 집단간의 신경섬유 경로는 부피와 밝기에 커다란 차이를 보인다. 특히, 신경섬유 경로의 부피에서 현저한 차이가 있다는 점은 알츠하이머의 조기 진단에 유용하게 사용될 수 있다.

Evaluation of the Neural Fiber Tractography Associated with Aging in the Normal Corpus Callosum Using the Diffusion Tensor Imaging (DTI) (확산텐서영상(Diffusion Tensor Imaging)을 이용한 정상 뇌량에서의 연령대별 신경섬유로의 변화)

  • Im, In-Chul;Goo, Eun-Hoe;Lee, Jae-Seung
    • Journal of the Korean Society of Radiology
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    • v.5 no.4
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    • pp.189-194
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    • 2011
  • This study used magnetic resonance diffusion tensor imaging (DTI) to quantitatively analyze the neural fiber tractography according to the age of normal corpus callosum and to evaluate of usefulness. The research was intended for the applicants of 60 persons that was in a good state of health with not brain or other disease. The test parameters were TR: 6650 ms, TE: 66 ms, FA: $90^{\circ}$, NEX: 2, thickness: 2 mm, no gap, FOV: 220 mm, b-value: $800s/mm^2$, sense factor: 2, acquisition matrix size: $2{\times}2{\times}2mm^3$, and the test time was 3 minutes 46 seconds. The evaluation method was constructed the color-cored FA map include to the skull vertex from the skull base in scan range. We set up the five ROI of corpus callosum of genu, anterior-mid body, posterior-mid body, isthmus, and splenium, tracking, respectively, and to quantitatively measured the length of neural fiber. As a result, the length of neural fiber, for the corpus callosum of genu was 20's: $61.8{\pm}6.8$, 30's: $63.9{\pm}3.8$, 40's: $65.5{\pm}6.4$, 50's: $57.8{\pm}6.0$, 60's: $58.9{\pm}4.5$, more than 70's: $54.1{\pm}8.1mm$, for the anterior-mid body was 20's: $54.8{\pm}8.8$, 30's: $58.5{\pm}7.9$, 40's: $54.8{\pm}7.8$, 50's: $56.1{\pm}10.2$, 60's: $48.5{\pm}6.2$, more than 70's: $48.6{\pm}8.3mm$, for the posterior-mid body was 20's: $72.7{\pm}9.1$, 30's: $61.6{\pm}9.1$, 40's: $60.9{\pm}10.5$, 50's: $61.4{\pm}11.7$, 60's: $54.9{\pm}10.0$, more than 70's: $53.1{\pm}10.5mm$, for the isthmus was 20's: $71.5{\pm}17.4$, 30's: $74.1{\pm}14.9$, 40's: $73.6{\pm}14.2$, 50's: $66.3{\pm}12.9$, 60's: $56.5{\pm}11.2$, more than 70's: $56.8{\pm}11.3mm$, and for the splenium was 20's: $82.6{\pm}6.8$, 30's: $86.9{\pm}6.4$, 40's: $83.1{\pm}7.1$, 50's: $81.5{\pm}7.4$, 60's: $78.6{\pm}6.0$, more than 70's: $80.55{\pm}8.6mm$. The length of neural fiber for normal corpus callosum were statistically significant in the genu(P=0.001), posterior-mid body(P=0.009), and istumus(P=0.012) of corpus callosum. In order of age, the length of neural fiber increased from 30s to 40s, as one grows older tended to decrease. For this reason, the nerve cells of brain could be confirmed through the neural fiber tractography to progress actively in middle age.

Evaluation of White Matter Abnormality in Mild Alzheimer Disease and Mild Cognitive Impairment Using Diffusion Tensor Imaging: A Comparison of Tract-Based Spatial Statistics with Voxel-Based Morphometry (확산텐서영상을 이용한 경도의 알츠하이머병 환자와 경도인지장애 환자의 뇌 백질의 이상평가: Tract-Based Spatial Statistics와 화소기반 형태분석 방법의 비교)

  • Lim, Hyun-Kyung;Kim, Sang-Joon;Choi, Choong-Gon;Lee, Jae-Hong;Kim, Seong-Yoon;Kim, Heng-Jun J.;Kim, Nam-Kug;Jahng, Geon-Ho
    • Investigative Magnetic Resonance Imaging
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    • v.16 no.2
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    • pp.115-123
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    • 2012
  • Purpose : To evaluate white matter abnormalities on diffusion tensor imaging (DTI) in patients with mild Alzheimer disease (AD) and mild cognitive impairment (MCI), using tract-based spatial statistics (TBSS) and voxel-based morphometry (VBM). Materials and Methods: DTI was performed in 21 patients with mild AD, in 13 with MCI and in 16 old healthy subjects. A fractional anisotropy (FA) map was generated for each participant and processed for voxel-based comparisons among the three groups using TBSS. For comparison, DTI data was processed using the VBM method, also. Results: TBSS showed that FA was significantly lower in the AD than in the old healthy group in the bilateral anterior and right posterior corona radiata, the posterior thalamic radiation, the right superior longitudinal fasciculus, the body of the corpus callosum, and the right precuneus gyrus. VBM identified additional areas of reduced FA, including both uncinates, the left parahippocampal white matter, and the right cingulum. There were no significant differences in FA between the AD and MCI groups, or between the MCI and old healthy groups. Conclusion: TBSS showed multifocal abnormalities in white matter integrity in patients with AD compared with old healthy group. VBM could detect more white matter lesions than TBSS, but with increased artifacts.

Semi-automated Tractography Analysis using a Allen Mouse Brain Atlas : Comparing DTI Acquisition between NEX and SNR (알렌 마우스 브레인 아틀라스를 이용한 반자동 신경섬유지도 분석 : 여기수와 신호대잡음비간의 DTI 획득 비교)

  • Im, Sang-Jin;Baek, Hyeon-Man
    • Journal of the Korean Society of Radiology
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    • v.14 no.2
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    • pp.157-168
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    • 2020
  • Advancements in segmentation methodology has made automatic segmentation of brain structures using structural images accurate and consistent. One method of automatic segmentation, which involves registering atlas information from template space to subject space, requires a high quality atlas with accurate boundaries for consistent segmentation. The Allen Mouse Brain Atlas, which has been widely accepted as a high quality reference of the mouse brain, has been used in various segmentations and can provide accurate coordinates and boundaries of mouse brain structures for tractography. Through probabilistic tractography, diffusion tensor images can be used to map comprehensive neuronal network of white matter pathways of the brain. Comparisons between neural networks of mouse and human brains showed that various clinical tests on mouse models were able to simulate disease pathology of human brains, increasing the importance of clinical mouse brain studies. However, differences between brain size of human and mouse brain has made it difficult to achieve the necessary image quality for analysis and the conditions for sufficient image quality such as a long scan time makes using live samples unrealistic. In order to secure a mouse brain image with a sufficient scan time, an Ex-vivo experiment of a mouse brain was conducted for this study. Using FSL, a tool for analyzing tensor images, we proposed a semi-automated segmentation and tractography analysis pipeline of the mouse brain and applied it to various mouse models. Also, in order to determine the useful signal-to-noise ratio of the diffusion tensor image acquired for the tractography analysis, images with various excitation numbers were compared.

Quantitative Evaluation of the Corticospinal Tract Segmented by Using Co-registered Functional MRI and Diffusion Tensor Tractography (정상인에서 기능적 뇌 자기공명영상과 확산텐서영상 합성기법을 이용한 피질척수로의 위치에 따른 정량적 분석)

  • Jang, Sung-Ho;Hong, Ji-Heon;Byun, Woo-Mok;Hwang, Chang-Ho;Yang, Dong-Seok
    • Investigative Magnetic Resonance Imaging
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    • v.13 no.1
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    • pp.40-46
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    • 2009
  • Purpose : The purpose of this study was to investigate the quantitative evaluation of the corticospinal tract (CST) at the multiple levels by using functional MRI (fMRI) co-registered to diffusion tensor tractography (DTT). Materials and Methods : Ten normal subjects without any history of neurological disorder participated in this study. fMRI was performed at 1.5 T MR scanner using hand grasp-release movement paradigm. DTT was performed by using DtiStudio on the basis of fiber assignment continuous tracking algorithm (FACT). The seed region of interest (ROI) was drawn in the area of maximum fMRI activation during the motor task of hand grasp-release movement on a 2-D fractional anisotropy (FA) color map, and the target ROI was drawn in the cortiocospinal portion of anterior lower pons. We have drawn five ROIs for the measurement of FA and apparent diffusion coefficient (ADC) along the corona radiata (CR) down to the medulla. Results : The contralateral primary sensorimotor cortex (SM1) was mainly found to be activated in all subjects. DTT showed that tracts originated from SM1 and ran to the medulla along the known pathway of the CST. In all subjects, FA values of the CST were higher at the level of the midbrain and posterior limb of internal capsule (PLIC) than the level of others. Conclusion : Our study showed that co-registered fMRI and DTT has elucidated the state of CST on 3-D and analyzed the quantitative values of FA and ADC at the multiple levels. We conclude that co-registered fMRI and DTT may be applied as a useful tool for clarifying and investigating the state of CST in the patients with brain injury.

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Diffusion Tensor Imaging and Cerebrospinal Fluid Flow Study of Cine Phase Contrast in Normal Cervical Spinal Cords (정상인 경수에 대한 확산텐서영상과 PC기법을 이용한 뇌척수액 속도 측정에 관한 연구)

  • Son, B.K.;Kwak, S.Y.;Han, Y.H.;Yoo, J.S.;Kim, O.H.;Ko, H.Y.;Mun, C.W.
    • Investigative Magnetic Resonance Imaging
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    • v.17 no.2
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    • pp.123-132
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    • 2013
  • Purpose : We report the results of the various parameters of diffusion tensor imaging (DTI) and CSF flow study of the cervical spinal cord using magnetic resonance (MR) imaging techniques. Materials and Methods: Intramedullary FA and MD were measured in the gray matter and posterior cord of the white matter and both lateral cords of the white matter at the C2-3, C4-5, C5-6 spinal levels. For the CSF flow study, velocity encoding was obtained at the C2-3, C4-5, C5-6 spinal levels. Results: There was a significant difference of the FA and MD between the white matter and gray matter (p < 0.05). The FA of the gray matter was significantly different according to the cervical spinal cord levels (p < 0.05). Otherwise, the FA and MD parameters were not significantly different (p > 0.05). The mean peak systolic velocity and mean peak diastolic velocity were $5.18{\pm}2.00cm/sec$ and $-7.32{\pm}3.18cm/sec$, respectively from C2 to C6 spinal cords. There was no significant difference in these velocities among the cervical spinal cord (p > 0.05). Conclusion: This basic information about DTI and CSF dynamics of the cervical spinal cord may be useful for assessing cervical spinal cord abnormalities using MR imaging.

Analysing the Governance of Regional Policies in the UK: Collaborative Relationships between Stakeholders within the Cambridge Technopole (영국 케임브리지 지역혁신정책상의 거버넌스 구조: 혁신주체간 협력관계를 중심으로)

  • Choi, Young-Chool
    • Journal of the Economic Geographical Society of Korea
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    • v.9 no.1
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    • pp.61-80
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    • 2006
  • The Cambridge Technopole has been recognised as one of the leading clusters in the world, and as such it has been benchmarked by other countries and other regions within the UK. This paper aims to analyse the governance of regional policies in the UK, with particular reference to the relationships between stakeholders operating within the Cambridge Technopole. Major findings of the research are as follows: The central government in the UK has been playing important roles as a customer, regulator and supporter of knowledge sources; Regional innovation policies across central departments have been co-ordinated by the DTI, so that overlapping of policies can be prevented; The policies of individual departments relating to regional innovation are co-ordinated by Government Offices for the Region(GOs) in each region, so that departmental sectionalism can be avoided. At the regional level, the EEDA established in the eastern region of England to which the Cambridge Technopole belongs is in charge of implementing all innovation policies within the region in a consolidated way. Networking organisations such as Cambridge Networks (CN) facilitate knowledge exchange between stakeholders, contributing to the building of mutual trust and creating a high level of social capital essential for regional innovation; The system for commercialising university technology and knowledge has been well institutionalised.

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Analysis of the Korean Real Estate Market and Boosting Policies Focusing on Mortgage Loans: Using System Dynamics (주택담보대출 규제 완화에 따른 부동산시장 영향 분석: 시스템다이내믹스 모형 개발)

  • Hwang, Sung-Joo;Park, Moon-Seo;Lee, Hyun-Soo;Yoon, You-Sang
    • Korean Journal of Construction Engineering and Management
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    • v.11 no.1
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    • pp.101-112
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    • 2010
  • The Korean real estate market currently is experiencing a slowdown due to the global economic crisis which has resulted from subprime mortgage lending practices. In response, the Korean government has enforced various policies, based on intend to deregulate real estate speculation, such as increasing the Loan to value ratio (LTV) in order to stimulate housing supply, demand and accompanying housing transactions. However, these policies have appeared to result in deep confusion in the Korean housing market. Furthermore, analyses for housing market forecasting particularly those which examine the impact of the international financial crisis on the Korean real estate market have been partial and fragmentary. Therefore, a comprehensive and systematical approach is required to analyze the real estate financial market and the causal nexus between market determining factors. Thus, with an integrated perspective and applying a system dynamics methodology, this paper proposes Korean Real Estate and Mortgage Market dynamics models based on the fundamental principles of housing markets, which are determined by supply and demand. As well, the potential effects of the Korean government's deregulation policies are considered by focusing on the main factor of these policies: the mortgage loan.

The Comparison of Right and Left Abdominal Temperature of dysmenorrhea patients using DITI (DITI를 이용한 월경통 여성의 좌우 복부온도 비교)

  • Kim, Seung-Hyun;Ahn, Soo-Jeong;Cho, Jung-Hoon;Jang, Jun-Bock;Lee, Kyung-Sub
    • Journal of Oriental Medical Thermology
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    • v.2 no.1
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    • pp.24-28
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    • 2003
  • Purpose: We aim to research the difference of abdominal temperature in dysmenorrhea patients comparing with that of normal person. Metholds: We selected the 49 dismenorrhea patients as study group and 54 normal persons as control group, excluding the patients who have dermatitis, ared over 70 or under 10. and have extreme obesity. We compared the 4 points(Rt and Lt Gimun(LR14) and Guirae(ST29)) in thd abdomen of both group, check the temperature of those points with DITI(Dorex, DTI-16UTI) to compare the temperature difference with each other. For statistics, we use independent T-test, SPSS 8.0 for windows. Results: The temperature difference between Rt and Lt Gimun which are in upper abdomen shows statistically significant result in study group. Conclusion: The dysmenorrhea patients show larger temperature difference between Rt and Lt points in upper abdomen than normal persons. In lower abdomen, the temperature between control and study group shows little difference.

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